Center-gage and micrometer



c. SNELL.

CENTERv GAGE AND MICROMETER. APPL |cM|oN min Nov. 4. |919.

1,365,289. y Patented .im 11,1921.-

BY: INVENTQR ww V@ Y ATTORNEYS sTATss UNITED FATENT QFFECE.

CHARLES SNELL, 0F HOUSTON, TEXAS.

Application filed November 4, 1919.

To all whom E may concern:

Be it known that I, CHARLES SNELL, a citizen of the United States,residing at Houston, in the county of Harris and State of Texas, haveinvented certain new and useful Improvements in- Center-Gages andMicrometers, ofwhich the following is a specification.

This invention relates to new and useful Improvements in a center gageand inside micrometer.

One object of the invention is to provide an implement of the characterdescribed, which has been specially designed ,for the purpose ofproviding a central support for dividers when the same are used inscribing castings and the like having a central bore. In finishingcasting such as cylinder heads and the like having a bore, it is oftennecessary to locate bolt holes around the fiange of the casting and inorder to describe the circle onwhich saidA holes are located, dividersare used, and when so used there must be a central support located atthe center of the bore. The device herein described has been designedfor the purpose of providing said support.

Another object of the invention is to provide an inside micrometer forthe purpose of accurately measuring the inside diameter of the bore andfor other similar purposes.

With the above and other objects in view, the invention has particularrelation to certain novel features of construction, use, and arrangementof parts, an example of which is given in this specification andillustrated in the accompanying drawings wherein Figure 1, is a sideelevation of the device,

Fig. 2, is an end view thereof,

Fig. 3, is a transverse sectional view taken on the line 8 3, of Fig. 2,

Fig. 4t, is a side elevation of the drive screw,

Fig. 5, is an end view thereof,

Fig. 6, is a side elevation of the adjusting sleeve, Y

Fig. 7, is a side elevation of the adjusting sleeve extension,

Fig. 8, is an end view thereof,

Fig. 9, is a side view of a form of extention employed when the deviceis used as an inside micrometer,

Fig. 10, is an end view thereof and,

Fig. 11, shows the complete device as applied to the work.

Referring now more particularly to the Specification of Letters Patent.

Patented Jan. 11, 1921,

Serial No. 335.654.

drawings wherein like numerals of reference designate similar parts, ineach of the figures, the numeral 1 refers to the tubular casing whichhas a bore extending from end to end, one end of said bore, beingreduced, forming the annular shoulder 2. The numeral 2 refers to thedrive screw whose ends are reversely threaded and said drive screw hasthe centrally7 located annular disk 8, formed integrally therewith. Thisdrive screw is located within the bore of the casing, one side of thedisk 8, fitting against the shoulder 2', and the other side of said diskhaving the rib 4, formed integrallyT therewith. Screwed on to therespective ends of the drive screw are the respective adjusting sleeves5 and 6, said sleeves fitting within the bore of the casing and thelatter having the sleeve like bushing 7, fitted thercaround.

The inner Aend of saidbushing fits against lthe disk 3, and has opposingnotches 8, 8,

which receive the rib 11, and clutch said bushing with the drive screw.The bushing 7 is retained in place by means of the cap 9, which isthreaded on to the corresponding end of the casing 1. The adjustingsleeves 5 and 6, have the respective key ways 10, 11 and set screws 12and 13 are threaded through the casing, 1, and cap 9, respectively, andtheir inner ends project into said key ways to hold the adjustingsleeves against turning, but they permit the lengthwise movement of saidsleeve on the drive screw. The top side of the casing, 1, is flattenedas at 1li and has the centrally located recess 15, which forms a centralsupport for the dividers when the same are used in scribing a circlearound the bore 16 of the casting 17.

In use, the device is placed in position within the bore and the bushing7 is then turned thus projecting the adjusting sleeves 5 and 6, cut ateach end until their outer ends engage against the walls of the bore tosupport the implement in position while in use. Thumb spaces 18, 18,Aare cut through the casing providing access to the bushing to turn thesame and the exposed'portion 19 of said bushing is knurled so that itmay be i more easily turned.

When usedin large bores, extensions 20 are attached to the respectiveends of the sleeves 5 and 6. The extension 20 is provided at one endwith a reduced stem 21 and. a transverse rib 22, said stem fittingwithin the outer end of the sleeve to which it is atdiameters ofdifferent bores.

tached and the rib 22 locking` in the transverse groove 23 in the cuterend oi" said sleeve.

The device may be also used as an inside micrometer for ascertaining`the diameter of the bore and for ascertaining` the relative lWhen usedVas a micrometer in large bores, the extensions 20 are attached to theouter ends of the sleeves 5 and 6 the reduced stem 2l fitting into theouter end of the sleeve to which it is attached and the transverse rib22, loci:- ing in the corresponding; transverse groove 23.

For use as a micrometer the exposed sec tion of the bushing' 7 has acircumferential gage 24 to measure the amount oi' the rotation of saidbushing* and the outer end et one of the adjusting sleeves is suitablygraduated as at 25 so that the distance it is projecting out from thecasing` may be accurately determined and the relative diameters ofdifferent bores, thus accurately ascertained.

What I claim is:

l. A device of the character described including a tubular casing, an:externally threaded drive screw located therein having a disk near thecenter thereof, a rib on one side of said disk, adjustable internallythreaded sleeves within said casing and threaded onto the respectiveends of said screw, a knurled bushing litted within said casing; andsurrounding one of said sleeves, said bushing' being connected to saidscrew through said rib, so as to rotate the same as the bushing isrotated, said casing having thumb spaces cut therethrough to permitaccess to the bushing for rotating the same.

2. A device ci' the character described, including' a tubular casing, arotatable drive screw therein formed with an annular disk, a rib on oneside of said disk, sleeves within the casing; and threaded on to therespective ends of said screw, a bushing having end notches into whichthe rib lits, said bushing surrounding one of said sleeves andoperatively connected to the drive screw whereby the latter may berotated, said casing having thumb spaces permitting' access to saidbushing whereby the same may be rotated, a circumferential gage formedon the bushing and a lengthwise gage formed on one of said sleeves.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES SNELL.

Vitnesses E. BUNGE, E. V. HARDWAY.

